/**
 * Copyright 2010-present Facebook.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.facebook;

import android.os.Handler;

import java.io.FilterOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Map;

class ProgressOutputStream extends FilterOutputStream implements RequestOutputStream
{
  private final Map<Request, RequestProgress> progressMap;
  private final RequestBatch requests;
  private final long threshold;

  private long batchProgress, lastReportedProgress, maxProgress;
  private RequestProgress currentRequestProgress;

  ProgressOutputStream(OutputStream out, RequestBatch requests, Map<Request, RequestProgress> progressMap, long maxProgress)
  {
    super(out);
    this.requests = requests;
    this.progressMap = progressMap;
    this.maxProgress = maxProgress;

    this.threshold = Settings.getOnProgressThreshold();
  }

  private void addProgress(long size)
  {
    if (currentRequestProgress != null)
    {
      currentRequestProgress.addProgress(size);
    }

    batchProgress += size;

    if (batchProgress >= lastReportedProgress + threshold || batchProgress >= maxProgress)
    {
      reportBatchProgress();
    }
  }

  private void reportBatchProgress()
  {
    if (batchProgress > lastReportedProgress)
    {
      for (RequestBatch.Callback callback : requests.getCallbacks())
      {
        if (callback instanceof RequestBatch.OnProgressCallback)
        {
          final Handler callbackHandler = requests.getCallbackHandler();

          // Keep copies to avoid threading issues
          final RequestBatch.OnProgressCallback progressCallback = (RequestBatch.OnProgressCallback) callback;
          if (callbackHandler == null)
          {
            progressCallback.onBatchProgress(requests, batchProgress, maxProgress);
          }
          else
          {
            callbackHandler.post(new Runnable()
            {
              @Override
              public void run()
              {
                progressCallback.onBatchProgress(requests, batchProgress, maxProgress);
              }
            });
          }
        }
      }

      lastReportedProgress = batchProgress;
    }
  }

  public void setCurrentRequest(Request request)
  {
    currentRequestProgress = request != null ? progressMap.get(request) : null;
  }

  long getBatchProgress()
  {
    return batchProgress;
  }

  long getMaxProgress()
  {
    return maxProgress;
  }

  @Override
  public void write(byte[] buffer) throws IOException
  {
    out.write(buffer);
    addProgress(buffer.length);
  }

  @Override
  public void write(byte[] buffer, int offset, int length) throws IOException
  {
    out.write(buffer, offset, length);
    addProgress(length);
  }

  @Override
  public void write(int oneByte) throws IOException
  {
    out.write(oneByte);
    addProgress(1);
  }

  @Override
  public void close() throws IOException
  {
    super.close();

    for (RequestProgress p : progressMap.values())
    {
      p.reportProgress();
    }

    reportBatchProgress();
  }
}
